Lindholm: Strikes outside the strike zone: skill or luck?

From Scott Lindholm at Beyond the Box Score on January 23, 2014, with mention of SABR member Daren Willman:

PITCHf/x data is both a blessing and curse. Sites like Brooks Baseball have changed the way pitching is viewed, but with over 700,000 pitches thrown each year, the amount of data can be overwhelming. The interface at Brooks is wonderful for individual pitchers, but doesn't allow for comparisons. This creates another instance where I can promote someone I've run across in the past six months and have really come to respect -- Daren Willman, who runs Baseball Savant. Part of his site includes a PITCHf/x search form that allows filtering through the approximate 4.2 million pitches thrown since 2008.

Searches need to be kept narrow since the amount of data can quickly become overwhelming. For this post, I wanted to find out how many pitches outside the strike zone were called strikes, and how many were called strikes vs. swinging strikes. I also was curious how often this happened with two strikes.

That's already too many questions, so I went with the last one--how often did a player strike out, either called or swinging, on balls outside the strike zone? I gathered the data and winnowed it down to a manageable set, choosing pitchers with at least 1,000 pitches, or 500 for current pitchers for a total of 863 pitchers.